SQL return a value at a specific date in time -

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i'm trying find value @ date.

my data looks like

date        value 2013-11-02   5 2013-10-10   8 2013-09-14   6 2013-08-15   4

how can determine value on 2013-09-30?

obviously answer 6 can't figure out sql code.

thanks

you can order by , limiting number of rows. in sql server syntax (and sybase , access):

select top 1 t.* table t date <= '2013-09-30' order date desc;

in mysql (and postgres):

select t.* table t date <= '2013-09-30' order date desc limit 1;

in oracle:

select t.* (select t.*       table t       date <= '2013-09-30'       order date desc     ) t rownum = 1

edit:

and, sql standard way (should work in database):

select t.* table t date = (select max(date)               table t2               date <= '2013-09-30'              );

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